How do lithium batteries do not charge after overdischarge

How do lithium batteries do not charge after overdischarge

How do lithium batteries do not charge after overdischarge? I bought a Sony Ericsson MP3 for half a year, and the use of MP3 lithium battery has been normal. Because the busy work, I left it idle for about a month, and forgot to hit the switch on the machine to the off position before it was used again to listen to the music. Then recharged it and could not be charged for a day. As the Sales Department of the machine has been transferred, the warranty is impossible, so fixed it by myself.

First, open the machine, take out the li ion battery inside and measure the maximum voltage is normal, indicating that the battery is not damaged. The reason may be that the li ion battery charger has a charging control link, and it can not charge enough for the overdischarged lithium ion battery. As a result, the 5V direct current is charged directly to the lead line of the battery. At the beginning, the charging current is very high (up to 400mA), and the current gradually decreases and stabilizes as the time goes on. After charging for 6 hours, the battery will be installed back to the wiring point of the original machine, and it will start to play normally. A few days later, when the amount of electricity is insufficient, the original li ion battery charger can be recharged again.